Home sellers -- and buyers -- spot a turnaround in '83

This year's housing outlook continues to brighten. ''A 30 percent increase in new home sales and housing construction is now forecast for 1983,'' according to a report by the National Association of Home Builders (NAHB).

''There's been a turnaround in all key housing indicators,'' the report goes on.

''Mortgage interest rates have plummeted from 18 to 12 percent levels (although fixed-rate mortgages were up slightly in January because of lender concern over federal government deficits), while construction starts, building permits, and home sales have shown new signs of life and are heading in the right direction for the first time in three years.''

Meanwhile, home prices, which appear to be gradually on the rise, are really decreasing.

A survey by the National Association of Realtors (NAR) lists the current median price of existing houses at $67,500. That's 2.3 percent higher than a year ago. However, as NAR concedes, when ''creative financing'' concessions are taken into account, home prices actually are lower than they were a year ago.

Indeed, the ''light at the end of the tunnel'' of the last few months has evolved into bright sunlight for builders and brokers alike - and the beneficiency is the home buyer and seller.

There is strong new activity in the marketing of resale homes, according to NAR. This is true both in regard to the number of people looking for houses to buy as well as in actual sales, the trade organization asserts.

Some real-estate researchers believe the effective reductions in home prices are very significant.

''If inflation and 'creative financing' are considered, there may be a real decrease in home prices of as much as 25 percent during the past year,'' says Stephen Roulac, president of Questor Associates in San Francisco.

In Mr. Roulac's opinion, the most significant factor is that home builders and sellers are contributing a part of the sale price to ''buy down,'' or reduce , the mortgage rate to make a house more attractive to prospective buyers. In 1981, he adds, US Home Corporation, the nation's largest, paid out 11 percent of its $1 billion revenues for buy-downs.

Taking over an existing mortgage is part of about 48 percent of home-sale transactions today, down from 60 percent a few months ago. And many sellers are still carrying back first or second mortgages (or trust deeds), sometimes at low interest rates, in their quest to find and close a buyer.

The NAR survey shows that brokers believe that interest rates on home loans, despite an occasional blip, will continue to decline over the next six months. This will make housing affordable for an increasingly large segment of US families.

A report from the Mortgage Bankers Association of America (MBA) also heralds the good news. It shows that the number of homeowners who are late on their mortgage payments is declining.

The decreasing number of delinquencies in mortgage payments is particularly welcome news at this time, in view of the serious employment problem in the US. Mark Riedy, executive vice-president of the MBA, stresses this point.

''As the plight of homeowners faced with the possibility of foreclosure became more apparent during the past year, several innovative programs were initiated to aid them,'' Riedy asserts.

''These included a federal program for temporary mortgage assistance for federally insured home loans, counseling services, and insurance programs offered by private mortgage insurance companies.''

Generally, the housing picture is bright and positive for the first time in more than three years.